package servlets;

import dbProcs.Getter;
import dbProcs.Setter;
import java.io.IOException;
import java.math.BigInteger;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import utils.ShepherdLogManager;
import utils.Validate;

/**
 * Control class for the Change Password function <br>
 * <br>
 * This file is part of the Security Shepherd Project.
 *
 * <p>The Security Shepherd project is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software Foundation, either
 * version 3 of the License, or (at your option) any later version.<br>
 *
 * <p>The Security Shepherd project is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU General Public License for more details.<br>
 *
 * <p>You should have received a copy of the GNU General Public License along with the Security
 * Shepherd project. If not, see <http://www.gnu.org/licenses/>.
 *
 * @author Mark Denihan
 */
public class ChangePassword extends HttpServlet {

  private static final long serialVersionUID = 1L;
  private static final Logger log = LogManager.getLogger(ChangePassword.class);

  /**
   * Initiated by index.jsp, getStarted.jsp. This changes a users password. If the user gets it
   * wrong 3 times in a row, they'll be locked out (This is handed by database)
   *
   * @param csrfToken
   * @param currentPassword User's current password
   * @param newPassword Submitted new password
   * @param passwordConfirmation Confirmation of the new password
   */
  public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    // Setting IpAddress To Log and taking header for original IP if forwarded from proxy
    ShepherdLogManager.setRequestIp(request.getRemoteAddr(), request.getHeader("X-Forwarded-For"));
    log.debug("*** servlets.ChangePassword ***");
    try {
      response.setCharacterEncoding("UTF-8");
      request.setCharacterEncoding("UTF-8");
      HttpSession ses = request.getSession(true);
      if (Validate.validateSession(ses)) {
        ShepherdLogManager.setRequestIp(
            request.getRemoteAddr(),
            request.getHeader("X-Forwarded-For"),
            ses.getAttribute("userName").toString());
        log.debug("Current User: " + ses.getAttribute("userName").toString());
        Cookie tokenCookie = Validate.getToken(request.getCookies());
        Object tokenParmeter = request.getParameter("csrfToken");
        if (Validate.validateTokens(tokenCookie, tokenParmeter)) {
          log.debug("Getting Parameters");
          String userName = (String) ses.getAttribute("userName");
          String currentPassword = (String) request.getParameter("currentPassword");
          String newPassword = (String) request.getParameter("newPassword");
          String passwordConfirm = (String) request.getParameter("passwordConfirmation");
          String ApplicationRoot = getServletContext().getRealPath("");

          boolean validData = false;
          boolean passwordChange = false;
          boolean validPassword = false;
          validData =
              newPassword.equalsIgnoreCase(passwordConfirm)
                  && !newPassword.isEmpty()
                  && newPassword != null;
          passwordChange = !currentPassword.equalsIgnoreCase(newPassword);
          validPassword = newPassword.length() > 4 && newPassword.length() <= 512;
          if (validData && passwordChange && validPassword) {
            log.debug("Validating Current Password");
            String user[] = Getter.authUser(ApplicationRoot, userName, currentPassword);
            if (user != null) {
              log.debug("User Credentials were good! Password Change gets the go ahead");
              Setter.updatePassword(ApplicationRoot, userName, currentPassword, newPassword);
              ses.setAttribute("ChangePassword", "false");
            } else {
              log.error("Incorrect Password");
              ses.setAttribute("errorMessage", "Incorrect Password... Don't lock yourself out!");
              response.sendRedirect("index.jsp");
              return;
            }
          } else {
            if (validData && passwordChange) {
              try {
                // User Account is Locked
                log.debug("The user account is locked. Logging the user out");
                Cookie cookieToken = Validate.getToken(request.getCookies());
                BigInteger temp = new BigInteger(cookieToken.getValue());
                response.sendRedirect("logout?csrfToken=" + temp);
              } catch (Exception e) {
                log.error(
                    "Cant Log the user out because they dont have a valid CSRF token : "
                        + e.toString());
                response.sendRedirect("login.jsp");
              }
            }
            // Return error message
            else if (!validData) {
              log.error("Bad Data Received");
              ses.setAttribute("errorMessage", "Invalid Request! Please try again.");
            } else if (!validPassword) {
              log.error("Invalid Password Submitted (Too Short/Long)");
              ses.setAttribute("errorMessage", "Invalid Password! Please try again.");
            } else {
              log.error("No password Change Detected");
              ses.setAttribute(
                  "errorMessage", "You have to CHANGE your password! Please try again.");
            }
          }
        } else {
          log.error("CSRF Attack Detected");
        }
      } else {
        log.error("Change Password Function Called with no valid session");
        response.sendRedirect("login.jsp");
      }
    } catch (Exception e) {
      log.fatal("ChangePassword Error: " + e.toString());
    }
    log.debug("*** END ChangePassword ***");
    response.sendRedirect("index.jsp");
  }
}
